The Meredith #3 Diversion modified an existing concrete diversion by constructing an engineered riffle over the existing structure after the structure had been chipped down below finish grade, installing a large rock apron and grade control structure downstream to stabilize the channel, installing a pool into the lower portion of the apron, installing a submerged headgate inlet box and creating an in-channel low flow passage channel.
The existing concrete structure was originally poured in place over a bedrock section of the creek bed. Fish passage was provided over the structure through a fish ladder installed by ODFW in 2004. However, the ladder did not meet current fish passage criteria during all flow conditions making the diversion a substantial fish passage barrier. The concrete barrier had headcut behind the structure, creating an approximate 3 ft jump in elevation from the water surface below the structure to the water surface above the structure.